The protein sequences of the seven human P2X family members were aligned using ClustalW (32), and the NetNGlyc 1.0 program was used to identify potential N-linked glycosylation sites (marked in red boxes). Identical residues are marked as black and chemically similar residues are marked as gray. The following protein accession numbers were used in the alignment: P2X1 AAC24494, P2X2 Q9UBL9, P2X3 NP_002550, P2X4 NP_002551, P2X5 AAH39015, P2X6 AAF13303, and P2X7 AAH11913.